This invention is directed to bis(salicylaldiato)titanium complex catalysts, and highly syndiotactic polypropylene makable therewith by a chain-end control mechanism, and block copolymers containing the syndiotactic polypropylene and poly(ethylene-co-propylene) and/or poly(alpha-olefin-co-propylene), as well as to living olefin polymers and to olefin terminated oligomers and polymers and to methods of making syndiotactic polypropylene, block copolymers and olefin-terminated oligomers and polymers from propylene.
The kind of polypropylene in general use, for example, for packaging and container functionality, is isotactic polypropylene. It is typically described as having the methyl groups attached to the tertiary carbon atoms of successive monomeric units on the same side of a hypothetical plane through the main chain of the polymer. Isotactic polypropylene lacks clarity and thus is not useful in cases where this is important.
Another kind of polypropylene is syndiotactic polypropylene. It may be described as having the methyl groups attached to the tertiary carbon of successive monomeric units on alternate sides of a hypothetical plane through the main chain of the polymer. Syndiotactic polypropylene is clear, that is it does not have the lack of clarity characteristic of isotactic polypropylene.
There are two types of syndiotactic polypropylene. One of these types is referred to as being made by a chain-end control mechanism and contains defects of the rmr type. NMR analysis for this kind of structure is shown in Zambelli, et al., Macromolecules, 13, 267-270 (1980). The most syndiospecific polypropylene of this type made before this invention has [rrrr] pentad content of 0.63 (described in Pellecchia, C., et al., Macromol. Rapid Commun. 17, 333-338 (1996)) which limits the usage since the lower the [rrrr] pentad content, the lower the melting point. For example, a container made from polypropylene with [rrrr] pentad content of 0.63 will melt on contact with boiling water and thus is unuseful for containers for hot liquids. We turn now to the other type of syndiotactic polypropylene. It is referred to as being made by a site-control mechanism and as containing defects of the rmmr type. This type of polypropylene is described in European Patent Application Publication 0351391 A2 (published Jan. 17, 1990). Highly syndiotactic polypropylene ([rrrr]=0.97) has been made by a site-control mechanism. See Ewen, J. A., et al., J. Am. Chem. Soc., 110, 6255-6256(1988), Herzog, T. A., et al., J. Am. Chem. Soc. 118, 11988-11989 (1996), and Veghini, D., et al., J. Am. Chem. Soc. 121, 564-573 (1999). This kind of syndiotactic polypropylene has not yet been commercialized apparently because of processing and/or economic factors.
It has been discovered herein that highly syndiospecific polypropylene can be made by a chain-control mechanism by utilizing certain bis(salicylaldiminato)titanium complex compounds as catalysts as well as block copolymers containing block(s) of the syndiotactic polypropylene and block(s) of poly(ethylene-co-propylene) and/or poly(alpha-olefin-co-propylene) and that living polymerization can be obtained and that certain of the catalysts are useful in the production of olefin terminated polymers and oligomers from propylene.
The invention herein in one embodiment, denoted the first embodiment, is directed to a bis(salicylaldiminato)titanium complex having the structure: 
where R is selected from the group consisting of halogen atoms, C1-C10 branched or straight chain alkyl groups, C1-C6 branched or straight chain alkoxide groups, and C1-C6 branched or straight chain amido groups, R1 is phenyl substituted with C1-C6 branched or straight chain alkyl group or electron withdrawing atom or group at the 2-position and optionally substituted with C1-C6 branched or straight chain alkyl groups or electron withdrawing atom or group at one or more of the 3-, 4-, 5- and 6-positions, or is C1-C10 branched, cyclic or straight chain alkyl group, and R2 and R3 are the same or different and are selected from the group consisting of C4-C6 tertiary alkyl groups; or cationic form thereof The complexes are useful as catalysts for polymerization of olefins and are especially useful for polymerization of propylene.
The invention herein in another embodiment, denoted the second embodiment, is directed to syndiotactic polypropylene having Mw ranging from 10,000 to 500,000 and defects of the type rmr and [rrrr] pentad content greater than 0.70. The syndiotactic polypropylene is useful, for example, for packaging and container functionality.
The invention herein in another embodiment, denoted the third embodiment, is directed to syndiotactic poly(C4-C6-alpha olefins) having a Mw ranging from 10,000 to 500,000 and Mw/Mn ranging from 1.0 to 2.0. These syndiotactic polyolefins are useful for films and sheets because of their flexibility and transparency.
The invention herein in another embodiment, denoted the fourth embodiment, is directed to a method of preparing syndiotactic polypropylene having Mw ranging from 10,000 to 500,000 and defects of the type rmr and [rrrr] pentad content greater than 0.50 comprising polymerizing propylene dissolved in an aprotic solvent in the presence of a catalytically effective amount of a complex having the structure: 
where R is selected from the group consisting of halogen atoms, C1-C10 branched or straight chain alkyl groups, C1-C6 branched or straight chain alkoxide groups, and C1-C6 branched or straight chain amido groups, R1 is phenyl optionally substituted with one to five C1-C6 branched or straight chain alkyl groups or one to five electron withdrawing atoms or groups, or is C1-C10 branched, cyclic or straight chain alkyl group, and R2 and R3 are the same or different and are selected from the group consisting of H or C1-C6 branched or straight chain alkyl group, and an activating effective amount of compound that converts titanium of the complex to cationic form. The syndiotactic polypropylene product has packaging and container functionality.
The invention herein in still another embodiment, denoted the fifth embodiment, is directed to olefin terminated polymers and oligomers of propylene having the structure: 
where n ranges from 1 to 750. These compounds are useful, for example, to add as so-called xe2x80x98macromonomersxe2x80x99 to other polymerizations and can be incorporated about as well as hexene.
The invention in another embodiment denoted the sixth embodiment is directed to a method of preparing polymers and oligomers of propylene having the structure (II) where n ranges from 1 to 750 comprising polymerizing propylene in an aprotic solvent in the presence of a catalytically effective amount of complex having the structure (I) where R is selected from the group consisting of halogen atoms, C1-C10 branched or straight chain alkyl groups, C1-C6 branched or straight chain alkoxide groups, and C1-C6 branched or straight chain amido groups, R1 is phenyl optionally substituted at one or more of the 3-, 4-, and 5-positions but not at the 2- and 6-positions, the optional substitution at one or more of the 3-, 4- and 5-positions being with C1-C6 branched or straight chain alkyl group or electron withdrawing atom or group, and R2 and R3 are the same or different and are selected from the group consisting of H and C1-C6 branched or straight chain alkyl groups and an activating effective amount of compound that converts titanium of the complex to cationic form, and quenching the reaction when olefin-terminated polymer or oligomer of desired number of monomer units is formed.
The invention herein in still another embodiment, denoted the seventh embodiment, is directed to block copolymer having Mw ranging from 10,000 to 500,000 comprising at least one block of syndiotactic polypropylene and at least one block of poly(ethylene/propylene) where the ethylene content ranges from 1 to 100% by weight, containing a volume fraction of syndiotactic polypropylene ranging from 0.20 to 0.99. Species include block copolymer consisting essentially of one block of syndiotactic polypropylene and one block of poly(ethylene-co-propylene), block copolymer consisting essentially of a block of syndiotactic polypropylene followed by a block of poly(ethylene-co-propylene) followed by a block of syndiotactic polypropylene, and block copolymer consisting essentially of a block of syndiotactic polypropylene followed by a block of poly(ethylene-co-propylene) followed by a block of syndiotactic polypropylene followed by a block of poly(ethylene-co-propylene) followed by a block of syndiotactic polypropylene.
The invention in still another embodiment, denoted the eighth embodiment is directed to block copolymer having Mw ranging from 10,000 to 500,000 comprising at least one block of syndiotactic polypropylene and at least one block of poly(alpha-olefin/propylene), e.g., poly(C4-C6 alpha-olefin/propylene), e.g., poly(1-butene/propylene) where the alpha-olefin content (not propylene) ranges from 1 to 100% by weight, containing a volume fraction of syndiotactic polypropylene ranging from 0.20 to 0.99.
Chain-end control and defects of the type rmr as referred to herein are described in Coates, G. W., Chem. Rev. 100, 1223-1252 (2000).
The [rrrr] pentad contents described herein are measured as described in Resconi, L., et al., Chem. Rev. 100, 1253-1345 (2000).
The term xe2x80x9celectron withdrawing atom or groupxe2x80x9d is used herein to mean atom or group where the connecting atom of the atom or group is more electronegative than hydrogen.
The term xe2x80x9cMwxe2x80x9d is used herein to mean weight average molecular weight, and the term xe2x80x9cMnxe2x80x9d is used herein to mean number average molecular weight and these are determined using gel permeation chromatography (GPC) in 1,2,4-trichlorobenzene at 140xc2x0 C. versus polystyrene standards, unless otherwise stated.